Pile driving hammer

ABSTRACT

The pile driving hammer includes a fluid cylinder and a piston mounted in the cylinder for reciprocal movement and connected to drive a heavy hammer, a fluid passage for supplying pressurized fluid to and exhausting the same from a lower end of the cylinder below the piston, valve means operable between a supply position and an exhaust position for controlling fluid flow into and out of said lower end of the cylinder via said fluid passage means, operator means for controlling said valve means in response to the position of said piston in said cylinder includes a hollow stem extending axially upward of the piston for communication between the upper end of the cylinder and externally thereof, a cam surface carried by said stem and a follower linkage engaging said cam surface is connected with said valve means for moving the same between said supply and exhaust position as said piston moves up and down within said cylinder.

United States Patent Warrington 1 1 PILE DRIVING HAMMER [75] Inventor:Henry G. Warrington, Palm Beach,

Fla

[73] Assignee: Vulcan lron Works Inc.,

Chattanooga, Tenn.

22 Filed: .lune4, 1973 21 Appl. No.: 366,778

1,257,762 2/1918 Sturtevant 91/352 1,292,429 1/1919 Bull 91/3521,894,799 1/1933 Smith, Jr i 91/349 3,053,231 9/1962 Fairchild 91/352 [4June 11, 1974 Primary Examiner-Paul E. Maslousky 5 7] ABSTRACT The piledriving hammer includes a fluid cylinder and a piston mounted in thecylinder for reciprocal movement and connected to drive a heavy hammer,a fluid passage for supplying pressurized fluid to and exhausting thesame from a lower end of the cylinder below the piston, valve meansoperable between a supply position and an exhaust position forcontrolling fluid flow into and out of said lower end of the cylindervia said fluid passage means, operator means for controlling said valvemeans in response to the position of said piston in said cylinderincludes a hollow stem extending axially upward of the piston forcommunication between the upper end of the cylinder and externallythereof, a cam surface carried by said stem and a follower linkageengaging said cam surface is connected with said valve means for movingthe same between said supply and exhaust position as said piston movesup and down within said cylinder.

6 Claims, 5 Drawing Figures PATENTEDJUM 1 1 1974 SHEET 2 BF 5PATENTEDJUN 1 1 i914 PILE DRIVING HAMMER The present invention relatesto a new and improved fluid powered pile driving hammer and is animprovement over the pile drivers shown and described in US. Pat. Nos.3,566,977 and No. 3,357,3l5, both of which patents are assigned to thesame assignee as the present application.

Fluid powered pile driving hammers generally include a cylinder andpiston operatively positioned therein with motor fluid being supplied toautomatically operate the piston for driving a heavy weight hammer orram connected thereto. The hammer or ram in turn directs impact drivingblows against pilings, or shoring members or other elements to bedriven. One common type of pile driver is classified as a single actinghammer and this type utilizes motive fluid for elevating the piston inonly one direction to raise the ram and thereafter when the fluid isexhausted from the cylinder, the piston and ram free fall downwardly tostrike a pile driving blow. The present invention relates to a singleacting type of hammer.

It is an object of the present invention to provide a new and improvedpile driving hammer.

Another object of the present invention is to provide a new andimproved. single acting, fluid powered pile driving hammer of thecharacter described.

Yet another object of the present invention is to provide a new andimproved pile driving hammer of the character described having a novelfluid passage and valve system and operator for controlling the actionof the hammer. I

Another object of the invention is to provide a new and improved piledriving hammer of the character described wherein a hollow exhaust stemconnected to the piston is provided for exhausting the upper end of thecylinder and for activating the fluid controlling valve system to cyclethe piston through driving in return strokes.

The foregoing and other objects and advantages of the present inventionare accomplished in an illustrative embodiment comprising a pile drivinghammer having a fluid cylinder and a piston mounted in the cylinder forreciprocal power and return strokes and connected to drive a heavyweight hammer or ram. Fluid passage means is provided for supplyingpressurized fluid to and exhausting the same from a lower end of thecylinder below the piston. Valvemeans movable between a supply positionand exhaust position is provided for controlling the fluid flow into andout of the lower end of the cylinder via the fluid passage means whichis controlled thereby. The hammer includes a dual purpose valve operatormeans in the form of a hollow stem extending axially upward of thepiston for controlling the valve means in response to the position ofthe piston in the cylinder, and for providing communication between theupper end of the cylinder and the atmosphere. A cam surface is providedon the stem and a follower linkage engageable by the cam is connectedwith the valve means to control the same for moving the piston ondriving and return strokes.

For a better understanding of the invention reference should be had tothe detailed description taken in conjunction with the drawings inwhich:

FIGS. IA and 18 comprise a vertical elevational view of a new andimproved fluid operated pile driving hammer constructed in accordancewith the features of the present invention with portions shown insection;

FIG. 2 is a transverse sectional view taken substantially along line 22of FIG. IA, and

FIG. 3 is another transverse sectional view taken substantially alonglines 33 of FIG. IA, and

FIG. 4 is another transverse sectional view taken substantially alonglines 4--4 of FIG. 1B.

Referring now more particularly to the drawings therein is illustrated anew and improved fluid operated pile driving hammer constructed inaccordance with the features of the present invention and generallyreferred to by the reference numeral 10. The pile driver l0is adapted tobe activated by compressible fluid such as steam or compressed air whichis supplied from a convenient source at the desired operating pressure.The size and weight of the piledriver 10 is designed and selected for aparticular operating pressure range in accordance with the powerrequirement needed for driving a particular type of piling or the like.I

The pile driver includes an elongated cylindrical body 12 having anannular base structure at the lower endin the form of a centering ring14. The centering ring is adapted to align the pile driver in coaxialvertical alignment with the piling to be driven and is formed with afrustroconical segment 16 at the lower end of an axial bore 18. The ring14 is supported at the lower end of a lower cylinder 20 by means of aplurality of tension members 22 the upper ends of which are extendedthrough ears formed on an intermediate wall structure 24 which dividesthe driver body 12 and separates the lower cylinder 20 from an upperfluid cylinder 26.

In the lower cylinder 20 a heavy weight hammer or ram 28 is mounted forvertical sliding movement and the ram is formed with an axial boretherein having an enlarged portion 30 at the lower end in whichis-carried an anvil member 32 adapted to impact the top end of thepilings with the heavy force required to drive the same. Rotation on theram within the cylinder 20 dur-- ing reciprocal movements is preventedby one or more keys 34 secured to the wall of the cylinder and adaptedto extend'into a slot 36 provided in the ram.

The heavy weight hammer-or ram 28 is interconnected to the lower end ofa piston shaft 38 which extends upwardly from the .anvil 32 through afluid tight annular seal structure 40 in the intermediate wall structure24. The lower end of the shaft 38 is coupled to the ram by pairs ofhorizontal tapered pins and sleeves 42 and 44 on opposite sides of theshaftQThe pins and sleeves are supported at opposite ends in oblongslots 46 formed in sidewall of the ram around the upper portion of theaxial bore thereof and are removable through window structures 48provided on the walls of the lower cylinder 20as best shown in FIG. 1Band FIG. 4. The pin and sleeves rest in grooves 50 provided in a pair ofstop members 52 on opposite sides of the piston shaft 38 and seated onan annular shoulder 54 at the lower end of the enlarged upper section 56of the axial bore of the hammer 28. The shaft 38 is enlarged at itslower end and is provided with several spaced apart annular rings 58which are seated in grooves provided in an annular coupling member 60carried in the middle portion 62 of the hammer bore between the enlargerlower and upper portions 30 and 56.

The upper end portion of the piston shaft 38 passes through the sealingunit 40 in the intermediate wall structure 24 into the lower end of thefluid cylinder 26 and is integrally connected to a piston 64 mounted inthe cylinder to supply the power for lifting the hammer 28. The upperend of the fluid cylinder is closed byan upper end wall structure orcylinder head 66 and an annular sealing structure 68 is mounted at thecenter of the head to seal around a hollow piston stem 70 extendingupwardly from the piston 64. The stem is open at its upper end tocommunicate with the atmosphere and is provided with a plurality of wallports 72 adjacent the lower end in communication with the interior ofthe fluid cylinder 26 above the piston 64 so that the upper end of thecylinder is maintained substantially at atmospheric pressure duringmovement of the piston on power and return strokes to lift and drop thehammer 28. When the piston is in a fully elevated upper position asshown in dotted lines in FIG. 1A, the ports 72 of the hollow stem areadjacent or above the level of the seal 68 in the cylinder head 66 sothat a small volume of air is entrapped in the upper end of the fluidcylinder 26 to act as a cushion and prevent the piston from striking theunderside ofthe cylinder head with great force.

As best shown in FIG. 1A, the upper end portion of the piston stem 70 isopen to exhaust the upper end of the cylinder and the stem is slidablewithin an upstanding stem housing or enclosure 74 secured to thecylinder head 66 and provided with a plurality of ports 76 adjacent theupper end on the side wall of the housing.

In order to lift the piston 64 on an upward stroke to raise the hammer28 to a position ready for release on a downward impact stroke, thecylinder is supplied with compressed fluid such as air or steam at thedesired pressure through a pair of radial ports or passages 78 formed inthe wall of the cylinder adjacent the lower end (FIGS. 1A, 2 and 3).These ports arein communication with the lower end of a pair ofcircumferential passages 80 (FIG. 3) formed in the wall structure of thefluid cylinder 26. Fluid flow into and out of the circumferentialpassages is controlled by a pair of rotary valves 82 disposed onopposite sides of the cylinder and supported for rotation in cylindricalvalve housings 84 integrally formed in the wall of the cylinder. Thevalve housings are provided with cylindrical, replaceable wall liners 86having ports therein as best shown in FIG. 3 and the housings areparallel with and on opposite sides of the central axis of the mainfluid cylinder 26 and the piston stem 70.

Each valve housing is closed at the lower end by an annular end wall 88(FIG. 1A) and at the upper end by a frustroconically shaped upstandingbearing structure 90 attached to the cylinder head 66. The valves 82 areof the cross section shown in FIG. 3 and are position controlled byvalvestems 92 joumalled at their lower ends in the members 88 and attheir upper ends by the structures 90. Fluid is supplied to the piledriver from a suitable source connected to a pair of inlet ports 94(FIG. 2) on the upper end wall of an integrally formed plenum chamber 96(FIG. 3) spaced midway between the valve chambers 84 and opposite thecylinder inlet ports 78. Fluid is delivered from the plenum chamber tothe valve chambers via apair of circumferential passages 98 formed inthe wall of the fluid cylinder 26.

Referring now to FIG. 3, with the valves 82 in the position shown,pressurized fluid from the plenum chamber 96 flows via the passages 98and short radial passages 100 through inlet ports 102 formed in thevalve chamber wall liner 86. This fluid fills the valve chambers andpasses through cylinder ports 104 in the liners, via radial passages 106into the passages 80 in communication with the cylinder wall ports 78below the piston 64. The pressurized fluid entering the lower end of thecylinder 26 cause the piston to move upwardly therein to elevate thehammer 28 ready for a downward impact stroke. When the piston reachesits upper position (dotted lines FIG. 1A) the valves 82 have beenrotated approximately 15 in a clockwise direction by their control stems92 so that the supply of incoming pressurized fluid to'the cylinder port104 is cut off by a rib 82a of the valve which is now positioned betweenthe fluid inlet port 102 and the cylinder port 104. A second rib 92b ofthe valve prevents inlet fluid from passing around the back side of thevalve chamber and out of an exhaust port 108 formed in-the liner tocommunicate with exhaust ports 110 formed in the wall of the valvehousing 84 (FIGS. 1A and 3). With the valve 82 in the shifted or exhaustposition as described, fluid from the underside of the piston 64 canpass rapidly out of the cylinder 26 via the ports 78, passages 80 and106, and ports I04 and 108 to the atmosphere through the valve chamberwall exhaust ports 110. When the underside of the piston 64 is vented tothe atmosphere as described, the piston and hammer 28 fall rapidlydownward on a power or driving stroke until the under surface of thedriving anvil 32 strikes the upper end or top surface of the piling onwhich the pile driver 10 is seated. At this point, downward travel ofthe piston 64 in the fluid cylinder 26 is arrested before the pistonstrikes the wall structure 24 closing off the lower end of the cylinder.

With the piston at its lower position (FIG. LA) at the end of a downwardpower or driving stroke, the valves 82 are shifted by rotation in acounterclockwise direction approximately 15 back to the supply positionas shown in FIG. 3 and the cycle is repeated for as many drive strokesas are needed to complete driving of the piling. On'the fluid poweredupward or return stroke of the cycle, the last portion of the stroke iscushioned by entrapped air in the upper end of the cylinder as the ports72 in the hollow stem are covered by the upper seal structure 68. On thedownward power stroke the piston is stopped short of the wall structure24 by the contact of the anvil member 32 with the piling. Both power andreturn strokes are thus automatically dampened at the end of the travel.

In order to operate the valves 82 in synchronism with the reciprocationof the hammer in response to the position of the piston the stem isprovided with a pair of elongated grooves 112 disposed on opposite sidesand extending at an acute shallow angle with respect to the longitudinalaxis of the hollow stem. Opposite sides of each groove serve as camsurfaces for engagement with follower pins I14 which project into thegrooves and are supported on the inside of an annular actuating collar116 (FIG. 2) mounted on the stem between the upper bearing 68 and thelower end of the stem housing 74 (FIG. 1A). The collar 116 is rotatableon the stem 70 and includes a pair of diametrically opposed ears 118which are pivotally interconnected to the inner ends of a pair of valveactuating arms 120. The arms 120 are pivotally interconnected at theirouter ends with short stem actuating arms I22 which are connected torotate the upwardly projecting end portions of the valve stem 92. Asshown in FIG. 1A, a radially extending arm 122 is keyed to rotate thestem 92 and is pivotally connected at its outer end to the outer end ofone of the actuating arms 120. Collars 124 are provided as spacers onthe stems 92 so that arms 122 are staggered for connection with theactuating arms. In order to prevent the stem 70 from rotatably drivingreciprocal strokes of the piston 64 the stem is provided with anotherpair of grooves 126 which are engaged by keys 128 on the inside of afixed seal collar 130 above the upper cylinder seal 68.

From the foregoing it will be seen that the hollow piston stem 70 servesa dual purpose in maintaining a continuous venting of the upper end ofthe cylinder 26 during piston reciprocation and providing an actuatingcam action for synchronizing the operation of the valves 82 and thepiston 64.

Although the present invention has been described with reference to asingle illustrative embodiment thereof, it should be understood thatnumerous other modifications and embodiments can be devised by thoseskilled in the art that will fall within the spirit and scope of theprinciples of this invention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

l. The combination in a pile driving hammer comprising: a fluidcylinder, a piston mounted in said cylinder for reciprocal movement onupstrokes and downstrokes and connected to drive a hammer below saidcylinder, fluid passage means for supplying pressurized fluid to andexhausting the same from a lower end of said cylinder below said piston,valve means operable between a supply position and an exhaust positionfor controlling fluid flow into and out of the lower end of saidcylinder via said fluid passage means, and operator means forcontrolling said valve in response to the position of said piston insaid cylinder, said operator means including a hollow stem extendingaxially upwardly of said piston and in communication between the upperend of said cylinder adjacent said piston and externally of saidcylinder adjacent the upper end of said stem, a cam surface carried bysaid stem and a follower linkage engaging said cam surface and connectedwith said valve means for moving the same between said supply positionand said exhaust position when said piston moves between a lowerposition and an upper position in said cylinder.

2. The combination of claim .1 wherein said valve means includes a pairof rotary valves on opposite sides of said cylinder rotatively movablebetween a first position supplying pressurized fluid through saidpassage means to the lower end of said cylinder and a second positionfor exhausting the fluid from the lower end of said piston to theatmosphere via a portion of said passage means.

3. The combination of claim 2 wherein said follower linkage includes acollar rotatably mounted on said stem including follower means inengagement with said cam surface carried thereby for rotativelyoscillating said collar as said piston reciprocates, arm meansinterconnecting said oscillating collar and said rotary valves to rotatethe latter between said first and second positions.

4. The combination of claim 3 wherein said cam surface includeselongated groove means formed on the outer surface of said stem andangularly inclined with respect to the longitudinal axis of said stemand means for preventing axial rotation of said stem as said pistonreciprocates.

5. The combination of claim 3 wherein said passage means includes afirst set of supply passages extending from a common fluid input chamberin opposite direc-' tions around said cylinder to said rotary valves anda second set of passages extending from said valves around said cylinderto a position opposite said input chamber and in communication with saidlower end of said cylinder via at least one radial port in the cylinderwall.

6. The combination of claim 5 wherein said passage means includes a pairof exhaust passages for communication between said rotary valves and theatmosphere, each valve including a rotary element operable tointerconnect a supply passage with a passage of said second set when insaid first position and to interconnect a passage of said second setwith an exhaust passage when in said second position.

1. The combination in a pile driving hammer comprising: a fluidcylinder, a piston mounted in said cylinder for reciprocal movement onupstrokes and downstrokes and connected to drive a hammer below saidcylinder, fluid passage means for supplying pressurized fluid to andexhausting the same from a lower end of said cylinder below said piston,valve means operable between a supply position and an exhaust positionfor controlling fluid flow into and out of the lower end of saidcylinder via said fluid passage means, and operator means forcontrolling said valve in response to the position of said piston insaid cylinder, said operator means including a hollow stem extendingaxially upwardly of said piston and in communication between the upperend of said cylinder adjacent said piston and externally of saidcylinder adjacent the upper end of said stem, a cam surface carried bysaid stem and a follower linkage engaging said cam surface and connectedwith said valve means for moving the same between said supply positionand said exhaust position when said piston moves between a lowerposition and an upper position in said cylinder.
 2. The combination ofclaim 1 wherein said valve means includes a pair of rotary valves onopposite sides of said cylinder rotatively movable between a firstposition supplying pressurized fluid through said passage means to thelower end of said cylinder and a second position for exhausting thefluid from the lower end of said piston to the atmosphere via a portionof said passage means.
 3. The combination of claim 2 wherein saidfollower linkage includes a collar rotatably mounted on said stemincluding follower means in engagement with said cam surface carriedthereby for rotatively oscillating said collar as said pistonreciprocates, arm means interconnecting said oscillating collar and saidrotary valves to rotate the latter between said first and secondpositions.
 4. The combination of claim 3 wherein said cam surfaceincludes elongated groove means formed on the outer surface of said stemand angularly inclined with respect to the longitudinal axis of saidstem and means for preventing axial rotation of said stem as said pistonreciprocates.
 5. The combination of claim 3 wherein said passage meansincludes a first set of supply passages extending from a common fluidinput chamber in opposite directions around said cylinder to said rotaryvalves and a second set of passages extending from said valves aroundsaid cylinder to a position opposite said input chamber and incommunication with said lower end of said cylinder via at least oneradial port in the cylinder wall.
 6. The combination of claim 5 whereinsaid passage means includes a pair of exhaust passages for communicationbetween said rotary valves and the atmosphere, each valve including arotary element operable to interconnect a supply passage with a passageof said second set when in said first position and to interconnect apassage of said second set with an exhaust passage when in said secondposition.